iankelling.org Git - distro-setup/blob - btrbk-run

   1 #!/bin/bash
   2 # Copyright (C) 2016 Ian Kelling
   3
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16
  17 # todo: if we cancel in the middle of a btrfs send, then run again immediately, the received subvolume doesn't get a Received UUID: field, and we won't mount it. Need to figure out a solution that will fix this.
  18
  19 set -eE -o pipefail
  20 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  21
  22 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
  23
  24 usage() {
  25   cat <<'EOF'
  26 btrbk-run [OPTIONS]
  27 usually -t TARGET_HOST
  28 EOF
  29   echo "top of script file:"
  30   sed -n '1,/^[# ]*end command line/{p;b};q' "$0"
  31   exit $1
  32 }
  33
  34 script_dir=$(dirname $(readlink -f "$BASH_SOURCE"))
  35
  36 # note q is owned by root:1000
  37 # note p/m is owned 1000:1000 and chmod 700
  38
  39
  40 mountpoints=()
  41
  42 rsync_mountpoint=/q
  43
  44 # default options
  45 conf_only=false
  46 dry_run=false # mostly for testing
  47 rate_limit=no
  48 verbose=true; verbose_arg=-v
  49 progress_arg="--progress"
  50
  51 default_args_file=/etc/btrbk-run.conf
  52 if [[ -s $default_args_file ]]; then
  53   set -- $(< $default_args_file) "$@"
  54 fi
  55
  56 temp=$(getopt -l help cl:m:npt:vh "$@") || usage 1
  57 eval set -- "$temp"
  58 while true; do
  59   case $1 in
  60     # only creates the config file, does not run btrbk
  61     -c) conf_only=true; shift ;;
  62     # bytes per second, suffix k m g
  63     -l) rate_limit=$2; shift 2 ;;
  64     # Comma separated mountpoints to backup. This has defaults set below.
  65     -m) IFS=, mountpoints=($2); unset IFS; shift 2 ;;
  66     -n) dry_run=true; dry_run_arg=-n; shift ;;
  67     -p) progress_arg="--progress"; shift ;;
  68     -q) verbose=false; verbose_arg=; progress_arg=; shift ;;
  69     # source host to receive a backup from
  70     -s) source=$2; shift 2 ;;
  71     # target hosts to send to. empty is valid for just doing local
  72     # snapshot. we have default hosts we will populate.
  73     -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  74     -v) verbose=true; verbose_arg=-v; shift ;;
  75     -h|--help) usage ;;
  76     --) shift; break ;;
  77     *) echo "$0: Internal error!" ; exit 1 ;;
  78   esac
  79 done
  80
  81 # usefull commands are resume and archive
  82 cmd_arg=${1:-run}
  83
  84 if [[ -s $default_args_file ]]; then
  85   echo "$0: warning: default btrbk-run options set in $default_args_file (sleeping 5 seconds):"
  86   cat $default_args_file
  87   sleep 5
  88 fi
  89
  90 if [[ -v targets && -v source ]]; then
  91   echo "$0: error: -t and -s are mutually exclusive" >&2
  92   exit 1
  93 fi
  94
  95 echo -e "$0: options: conf_only=$conf_only\ndry_run=$dry_run\nrate_limit=$rate_limit\nverbose=$verbose\ncmd_arg=$cmd_arg"
  96
  97 # set default targets
  98 if [[ ! -v targets && ! -v source ]]; then
  99   case $HOSTNAME in
 100     x2|kw)
 101       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 102         targets=($HOME_DOMAIN)
 103       fi
 104       ;;
 105     tp)
 106       targets=(frodo)
 107       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 108         if timeout -s 9 10 ssh x2 :; then
 109           targets+=(x2)
 110         fi
 111       fi
 112       ;;
 113     frodo)
 114       targets=()
 115       ;;
 116     *)
 117       echo "$0: error: no default targets for this host, use -t"
 118       exit 1
 119       ;;
 120   esac
 121 fi
 122
 123 if [[ -v targets ]]; then
 124   echo "targets: ${targets[*]}"
 125 fi
 126
 127 if [[ -v source ]]; then
 128   echo "source: $source"
 129 fi
 130
 131
 132
 133 # set default mountpoints
 134 case $HOSTNAME in
 135   # no remote backups atm. note, if we do enable this, configuration below will need some changes.
 136   #  frodo)
 137   #    prospective_mps=(/i)
 138   #    ;;
 139   *)
 140     prospective_mps=(/a /q)
 141     if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 142       prospective_mps+=(/o)
 143     fi
 144     ;;
 145 esac
 146 case ${targets[0]} in
 147   kw|kww)
 148     prospective_mps=(/a)
 149     ;;
 150 esac
 151
 152 for mp in ${prospective_mps[@]}; do # default mountpoints to sync
 153   if [[ -e /nocow/btrfs-stale/$mp ]]; then
 154     echo "$0: warning: $mp stale, not adding to default mountpoints"
 155     continue
 156   fi
 157   if awk '{print $2}' /etc/fstab | grep -xF $mp &>/dev/null; then
 158     mountpoints+=($mp)
 159   fi
 160 done
 161
 162 echo "mountpoints: ${mountpoints[*]}"
 163
 164 ##### end command line parsing ########
 165
 166 rsync-dirs() {
 167   local host=$1
 168   local path=$2
 169   m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
 170 }
 171
 172
 173 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
 174
 175
 176 if ! which btrbk &>/dev/null; then
 177   echo "$0: error: no btrbk binary found"
 178   exit 1
 179 fi
 180 # if our mountpoints are from stale snapshots,
 181 # it doesn't make sense to do a backup.
 182 check-subvol-stale ${mountpoints[@]} || exit 1
 183
 184
 185 cat >/etc/btrbk.conf <<EOF
 186 ssh_identity /root/.ssh/home
 187 # Just a guess that local7 is a good facility to pick.
 188 # It's a bit odd that the transaction log has to be logged to
 189 # a file or syslog, while other output is sent to std out.
 190 # The man does not mention a way for them to be together, but
 191 # I dunno if setting a log level like warn might also output
 192 # transaction info.
 193 transaction_syslog local7
 194
 195 # 20%ish speedup[]
 196 stream_buffer 512m
 197
 198 # so we only run one at a time
 199 lockfile                   /var/lock/btrbk.lock
 200
 201 # default format of short does not accomidate hourly preservation setting
 202 timestamp_format long-iso
 203
 204 # only make a snapshot if things have changed
 205 snapshot_create onchange
 206 # I could make this different from target_preserve,
 207 # if one disk had less space.
 208 # for now, keeping them equal.
 209 snapshot_preserve 36h 14d 8w 24m
 210 snapshot_preserve_min 4h
 211 snapshot_dir btrbk
 212
 213 # so, total backups = ~89
 214 target_preserve 36h 14d 8w 24m
 215 target_preserve_min 4h
 216
 217 # if something fails and it's not obvious, try doing
 218 # btrbk -l debug -v dryrun
 219
 220 rate_limit $rate_limit
 221 EOF
 222
 223
 224
 225 for tg in ${targets[@]:-localhost}; do
 226   # for an initial run, btrbk requires the dir to exist.
 227   ssh root@$tg mkdir -p /mnt/root/btrbk
 228 done
 229
 230
 231
 232 vol=/mnt/root
 233 for m in ${mountpoints[@]}; do
 234   sub=${m##*/}
 235   if [[ -v source ]]; then
 236     cat >>/etc/btrbk.conf <<EOF
 237 volume ssh://$source$vol/btrbk
 238 subvolume $sub
 239 target send-receive $vol/btrbk
 240 EOF
 241   else
 242     cat >>/etc/btrbk.conf <<EOF
 243 volume $vol
 244 subvolume $sub
 245 EOF
 246     for tg in ${targets[@]}; do
 247       cat >>/etc/btrbk.conf <<EOF
 248 target send-receive ssh://$tg$vol/btrbk
 249 EOF
 250     done
 251   fi
 252 done
 253
 254
 255 # todo: umount first to ensure we don't have any errors
 256 # todo: do some kill fuser stuff to make umount more reliable
 257
 258
 259 if $conf_only; then
 260   exit
 261 fi
 262
 263
 264
 265 if $dry_run; then
 266   m btrbk -v -n $cmd_arg
 267 elif [[ $cmd_arg == archive ]]; then
 268   if [[ -v source ]]; then
 269     m btrbk $verbose_arg $progress_arg $cmd_arg ssh://$source$vol $vol
 270   else
 271     for tg in ${targets[@]}; do
 272       m btrbk $verbose_arg $progress_arg $cmd_arg $vol ssh://$tg$vol
 273     done
 274   fi
 275 else
 276   # -q and just using the syslog option seemed nice,
 277   # but it doesn't show when a send has a parent and when it doesn't.
 278   m btrbk $verbose_arg $progress_arg $cmd_arg
 279 fi
 280
 281 # if we have it, sync to systems which don't
 282 if mountpoint $rsync_mountpoint >/dev/null; then
 283   for tg in ${targets[@]}; do
 284     case $tg in
 285       li|lk)
 286         for x in /p/c/machine_specific/*.hosts; do
 287           if grep -qxF $tg $x; then
 288             dir=${x%.hosts}
 289             rsync-dirs $tg $dir
 290           fi
 291         done
 292         ;;
 293     esac
 294   done
 295 fi
 296
 297 if ! $dry_run; then
 298   # note, targets will be empty if source is set.
 299   m $script_dir/mount-latest-remote ${targets[@]}
 300 fi
 301
 302
 303 # todo: move variable data we don't care about backing up
 304 # to /nocow and symlink it.
 305
 306
 307 # background on btrbk timezones. with short/long, timestamps use local time.
 308 # for long, if your local time moves backwards, by moving timezones or
 309 # for an hour when daylight savings changes it, you will temporarily get
 310 # a more aggressive retention policy for the overlapping period, and
 311 # vice versa for the opposite timezone move. The alternative is using
 312 # long-iso, which puts timezone info into the timestamp, which means
 313 # that instead of shifting time, you shift the start of day/week/month
 314 # which is used for retention to your new local time, which means for
 315 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 316 # retention will be 8 hours more aggressive since midnight is at a new
 317 # time, unless you fake the timzeone using the TZ env variable.
 318 # However, in the short term, there will be no inconsistencies.
 319 # I don't see any problem with shifting when the day starts for
 320 # retention, so I'm using long-iso.
 321
 322 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z